Anlysis And Control The Noise Of Low Pressure Gear Pump

Due to the high cost performance, gear pump plays the key role in middle and low pressure system, lubrication system, which will be developed to fast response, small volume, low noise, high pressure, large displacement, and low noise.There are a lot of noise study of gear pump, but most of them are consider on relief slot, bleed slot, lub slot and so on. It is very limited knowledge about the manufacture error of gear, which cause the loud noise.This study is base on the meshing dynamics model, depends on test result from air-borne, pressure pluse and acceleration. It is consider every manufacture error (include tooth profile modification, crown, pitch error, pitch run-out and pitch run-out of spline , different material. Then it calculates the time-varying meshing stiffness, gets the result of vibration due to the manufacture error, and transfers it to acceleration at last. The result is compared with test report. If they have the same extend, the reason of high noise and solution are found.The conclusion is that: (1) gear precision affects the noise level, but not so much; (2) most noise problem is from connection tolerance, process weakness, and low capability of domestic process. (3) Through the calculation, give a little higher requirement to supplier; improve other side of gear, then control the noise. In this study, change the spline run-out from 0.2mm to 0.12mm, improve the tooth surface. There is 1 to 2 dBA difference between local pump and master pump.